﻿//
// (C) Copyright 2009 Irantha Suwandarathna (iranthas@hotmail.com)
// All rights reserved.
//

/* Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using EffiProz.Core.RowIO;
using EffiProz.Core.Lib;
using EffiProz.Core.Store;
using EffiProz.Core.Errors;

namespace EffiProz.Core.Persist
{
    public class DataFileCacheSession : DataFileCache
    {
        // We are using persist.Logger-instance-specific FrameworkLogger
        // because it is Database-instance specific.
        // If add any static level logging, should instantiate a standard,
        // context-agnostic FrameworkLogger for that purpose.
        public int storeCount;

        public DataFileCacheSession(Database db, String baseFileName)
            : base(db, baseFileName)
        {

        }

        /**
         * Initial external parameters are set here. The size if fixed.
         */
        protected override void initParams(Database database, String baseFileName)
        {

            this.dataFileName = baseFileName + ".data.tmp";
            this.database = database;
            fa = FileUtil.GetDefaultInstance();

            int cacheSizeScale = 10;

            cacheFileScale = 8;

            Error.printSystemOut("cache_size_scale: " + cacheSizeScale);

            maxCacheRows = 2048;

            int avgRowBytes = 1 << cacheSizeScale;

            maxCacheBytes = maxCacheRows * avgRowBytes;
            maxDataFileSize = (long)int.MaxValue * 4;
            dataFile = null;
        }

        /**
         * Opens the *.data file for this cache.
         */
        public override void open(bool rdy)
        {

            try
            {
                dataFile = ScaledRAFile.newScaledRAFile(database, dataFileName,
                        false, ScaledRAFile.DATA_FILE_RAF);
                fileFreePosition = INITIAL_FREE_POS;

                initBuffers();

                freeBlocks = new DataFileBlockManager(0, cacheFileScale, 0);
            }
            catch (Exception t)
            {
                database.logger.logWarningEvent("Failed to open RA file", t);
                close(false);

                throw Error.error(t, ErrorCode.FILE_IO_ERROR,
                                  ErrorCode.M_DataFileCache_open, new Object[] {
                t.Message, dataFileName
            });
            }
        }

        public override void add(CachedObject obj)
        {
            lock (this)
            {
                base.add(obj);
            }
        }

        /**
         *  Parameter write is always false. The backing file is simply closed and
         *  deleted.
         */
        public override void close(bool write)
        {
            lock (this)
            {
                try
                {
                    if (dataFile != null)
                    {
                        dataFile.close();

                        dataFile = null;

                        fa.removeElement(dataFileName);
                    }
                }
                catch (Exception t)
                {
                    database.logger.logWarningEvent("Failed to close RA file", t);

                    throw Error.error(t, ErrorCode.FILE_IO_ERROR,
                                      ErrorCode.M_DataFileCache_close, new Object[] {
                t.Message, dataFileName
            });
                }
            }
        }

        public void postClose(bool keep) { }

        public void clear()
        {

            cache.clear();

            fileFreePosition = INITIAL_FREE_POS;
        }

        public void deleteAll()
        {

            cache.clear();

            fileFreePosition = INITIAL_FREE_POS;

            initBuffers();
        }
    }
}
